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Degradation of nuclear proteins: studies on transplanted B82 cell karyoplast proteins
Author(s) -
Fernig David G.,
Mayer R.John
Publication year - 1987
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(87)81329-7
Subject(s) - cytoplasm , leupeptin , nucleus , sendai virus , cytochalasin b , microbiology and biotechnology , nuclear protein , cell nucleus , biology , cell fusion , cell , chemistry , biochemistry , protease , gene , enzyme , transcription factor
Karyoplasts were prepared from B82 cells (thymidine kinase deficient mouse L cells) by cytochalasin B mediated enucleation. Morphological measurements show that the nucleus constitutes 89% of a karyoplast by volume. Homokaryons were obtained by Sendai virus mediated karyoplast‐B82 cell fusion. Transplanted nuclei were not destroyed catastrophically but were maintained intracellularly for at least 140 h. Transplanted nuclear proteins were degraded with an average half‐life of 84 ± 7 h by processes partially sensitive to inhibition by NH 4 Cl (50%) and leupeptin (30%). The data therefore suggest that some nuclear proteins are translocated to the cytoplasm for lysosomal degradation.